Natural alternative heme-environments allow efficient peroxygenase activity by cytochrome P450 monooxygenases

Abstract

Mild oxyfunctionalization reactions driven by hydrogen peroxide using cytochrome P450 monooxygenases with alternative heme environments.

The selective oxidation of thioanisole to sulfoxide using a highly efficient electroenzymatic cascade system

“…Alternatively, the thioanisole acts as a two-electron donor to reduce Compound I and return directly to the resting state of CPO (step b), 31 while the sulphur atom in the thioanisole receives an oxygen and is oxidized to the sulfoxide. 8…”

“…5,6 Besides, sulfoxide preparation usually requires oxidizers such as potassium periodate, hydrogen peroxide, sodium hypochlorite, and potassium persulfate. 7,8 At present, this method has the disadvantages of low selectivity, long reaction time, generation of highly toxic waste, and poor recycling. 9 Given this, it is urgent to develop mild and green methods to catalyze the oxidation of thioethers for sulfoxide synthesis.…”

Emerging Strategies for Modifying Cytochrome P450 Monooxygenases into Peroxizymes

“…14 Natural P450s containing an aspartate instead of the conventional threonine on the distal side of the heme have also been shown to allow efficient peroxygenase activity. 15 Many natural oxidizing enzymes belonging to the larger family of heme proteins, such as horseradish peroxidase (HRP), catalase, and unspecific peroxygenases (UPO), can effectively utilize H 2 O 2 . 16 Given the rich substrate diversity and enormous synthetic application potential, getting P450s to effectively employ their peroxideshunt pathway to convert the NAD(P)H-dependent monooxygenase mode (Figure 1B) into the peroxizyme mode (Figure 1C) will greatly expand their chemical space and open alternative avenues for developing practical P450 biocatalysts.…”

“…ATCC 8456, which can directly utilize H 2 O 2 rather than O 2 as the terminal oxidant to perform its catalytic functions . Natural P450s containing an aspartate instead of the conventional threonine on the distal side of the heme have also been shown to allow efficient peroxygenase activity . Many natural oxidizing enzymes belonging to the larger family of heme proteins, such as horseradish peroxidase (HRP), catalase, and unspecific peroxygenases (UPO), can effectively utilize H 2 O 2 .…”

Engineering Peroxygenase Activity into Cytochrome P450 Monooxygenases through Modification of the Oxygen Binding Region

“…When H 2 O 2 is used to support catalysis, costly nicotinamide cofactors (e.g., NAD­(P)­H) and additional electron transfer partner proteins are no longer required . However, the majority of CYPs are unable to use H 2 O 2 efficiently. , Peroxides can also destroy the heme or oxidize the heme-bound cysteine ligand, resulting in loss of activity. − If CYPs could be engineered to use H 2 O 2 more efficiently, it would enable them to be more widely used in synthetic procedures, which require C–H bond oxidations and complement existing chemical and biocatalytic methods and enable new highly selective reactions on a broader range of substrates. − …”